Generally, a water supply valve, which is configured to control the temperature and flow rate of water when supplying water, means a water control valve that controls the flow rate of water supplied from an outside water source (including hot water supplied from a boiler) and controls the temperature of water by selecting cold water or hot water, or by mixing cold water and hot water.
The water supply valve capable of controlling the temperature and flow rate of water may be installed in a kitchen, at an appropriate position above a sink, or in a bathroom (including a public bath), at a predetermined position so that a user can easily use water by manipulating the valve as desired.
Conventional water supply valves to control the temperature and flow rate of water when supplying water have been classified into knob-operated valves, which can control the flow rate and temperature of water by manipulating rotary knobs to select cold water or hot water or to mix the cold water and hot water, and lever-operated valves, which can control the flow rate of water by moving a lever upwards or downwards and control the temperature of water by rotating the lever leftwards or rightwards to select cold water, hot water, or a mix of the cold water and hot water.
Described in detail, in conventional knob-operated water supply valves, a cold water knob, which is manipulated to discharge cold water at a controlled flow rate, and a hot water knob, which is manipulated to discharge hot water at a controlled flow rate, are provided on opposite sides of a valve body. Thus, when it is desired to use cold water or hot water exclusively, a user can easily control the flow rate of water by manipulating a knob designated for cold water or hot water. However, when it is desired to use mixed water of a desired temperature (between the temperature of hot water and the temperature of cold water), the two knobs (for cold water and hot water) must be carefully manipulated to provide the desired temperature so that the knobs trouble users while manipulating the knobs and the knob-operated valves are inconvenient to the users.
Particularly, the conventional knob-operated valves each have a plurality of valve cartridges used for separately controlling the flow rates of cold water and hot water. Thus, the valve cartridges of each of the conventional knob-operated valves comprise many elements, complicating the construction of the water supply valves.
Furthermore, the plurality of valve cartridges having many elements causes the conventional knob-operated valves to have a complex and crude appearance. Thus, the conventional knob-operated valves do not appeal to the taste of modern people preferring a simple and refined appearance and, furthermore, increase production costs thereof.
The conventional lever-operated water supply valves are problematic in that they needlessly waste an excessive amount of water because the lever-operated valves cannot precisely control the flow rate of water, unlike the knob-operated valves. Furthermore, the conventional lever-operated valves become worn at frictional contact surfaces thereof by use over a lengthy period, causing leakage of water from the junctions of the worn contact surfaces.
Particularly, most conventional lever-operated valves have one lever (because they are designed as single lever-type valves), thus causing a manipulation problem in which the valves may change the existing flow rate of water during temperature control operation and change the existing temperature of water during flow rate control operation.
Described in detail, because the conventional lever-operated water supply valve has a single lever to control the temperature and flow rate of water, a user must control the temperature and flow rate of water by manipulating the single lever as follows. To control the temperature of water, the user manipulates the single lever so that a control disk of the valve is rotated leftwards or rightwards, thereby adjusting the opening ratios of hot and cold water inlet holes and controlling the mixing ratio of hot and cold water, and controlling the temperature of water to be discharged from the valve. To control the flow rate of water, the user manipulates the single lever to move the control disk forwards or backwards, thus adjusting the opening ratio of a water discharge hole and controlling the flow rate of water to be discharged from the valve. Thus, the conventional lever-operated valves having single valves cause the above-mentioned manipulation problem.
Furthermore, in operation of the above-mentioned lever-operated valves, the lever cannot be precisely manipulated, so that excessive time is required to control the temperature of water to a desired point during which an excessive amount of water is discharged from the valve and is needlessly wasted. In addition, users may unintentionally fully open the lever-operated valves, thereby wasting an excessive amount of water.
In an effort to overcome the above-mentioned problems, the present inventor proposed a water supply valve in Korean Patent Application No. 10-2004-0099326, filed on Nov. 30, 2004.
As shown in FIG. 1, the water supply valve proposed by the present inventor, which is configured to control the temperature of water by appropriately mixing hot water and cold water and control the flow rate of the hot water, cold water or a mix of the hot and cold water, includes a valve cartridge 100. The valve cartridge 100 includes: a first fixed disk 120 to separately guide hot water and cold water flowing from the outside into the valve cartridge; a first rotary disk 130 to rotate in relation to the first fixed disk 120 and control the temperature of water according to the amount of mixed water of cold water and hot water; a second fixed disk 140 to guide hot water and cold water flowing from the first rotary disk 130 into the valve cartridge through a water inlet path; and a second rotary disk 150 to control the amount of discharged water of hot water and cold water flowing from the second fixed disk 140. The valve cartridge 100 is installed in a valve body 200, with the first rotary disk 130 placed in the cartridge to be rotated by a temperature control unit 170. Furthermore, the second rotary disk 150 is concentrically rotated relative to the temperature control unit 170 by a flow rate control unit 160. The above-mentioned disks 120, 130, 140 and 150 have respective water discharge holes at positions aligned with each other, thus defining a water discharge path.
However, the above-mentioned water supply valve having the improved structure is problematic in that the diameter of the second rotary disk, which is in surface contact with and rotates relative to the second fixed disk so as to open or close the water inlet path and the water discharge path, is equal to that of the second fixed disk, so that the two disks have a large contact surface area, increasing friction between them.
Due to the above-mentioned problem, the second rotary disk is not easy to manipulate, thus reducing manipulation efficiency. Furthermore, due to the large contact surface area, managing flatness allowance of the disks is not easy.